Q90.1Billable

Trisomy 21, mosaicism (mitotic nondisjunction)

Chapter
17. Congenital malformations, deformations and chromosomal abnormalities
Category
Q90
Effective date
October 1, 2026

Related codes in category Q90

Q90Down syndromeQ90.0Trisomy 21, nonmosaicism (meiotic nondisjunction)YesQ90.2Trisomy 21, translocationYesQ90.9Down syndrome, unspecifiedYes

Frequently asked questions

What is ICD-10 code Q90.1?

Q90.1 is an ICD-10-CM diagnosis code for Trisomy 21, mosaicism (mitotic nondisjunction).

Is Q90.1 a billable code?

Yes. Q90.1 is billable and specific enough to be used on a claim.

What ICD-10-CM chapter is Q90.1 in?

Q90.1 falls under Chapter 17: Congenital malformations, deformations and chromosomal abnormalities.

When did Q90.1 become effective?

Q90.1 has been effective since October 1, 2026, per the CMS/CDC ICD-10-CM annual release.

What other codes are related to Q90.1?

Q90.1 belongs to category Q90, which includes 4 other codes — see the related codes list on this page.

ICD-10-CM data maintained by CDC/CMS (public domain). Always verify codes with authoritative sources before making coding or billing decisions.